Problem: Khan.scratchpad.disable(); For every level Nadia completes in her favorite game, she earns $870$ points. Nadia already has $400$ points in the game and wants to end up with at least $3810$ points before she goes to bed. What is the minimum number of complete levels that Nadia needs to complete to reach her goal?
Explanation: To solve this, let's set up an expression to show how many points Nadia will have after each level. Number of points $=$ $ $ Levels completed $\times$ Points per level $+$ Starting points Since Nadia wants to have at least $3810$ points before going to bed, we can set up an inequality. Number of points $\geq 3810$ Levels completed $\times$ Points per level $+$ Starting points $\geq 3810$ We are solving for the number of levels to be completed, so let the number of levels be represented by the variable $x$ We can now plug in: $x \cdot 870 + 400 \geq 3810$ $ x \cdot 870 \geq 3810 - 400 $ $ x \cdot 870 \geq 3410 $ $x \geq \dfrac{3410}{870} \approx 3.92$ Since Nadia won't get points unless she completes the entire level, we round $3.92$ up to $4$ Nadia must complete at least 4 levels.